1. Field of the Invention
The present invention is related to an apparatus for monitoring vacuum levels; and more specifically, to an apparatus suitable for monitoring the vacuum level exerted by any type of vacuum gripper or suction cup.
2. Description of Related Art
Vacuum grippers or lifters are a reliable, efficient and ergonomic means of handling any smooth, nonporous material, including glass, metal, stone, concrete, plastic and laminates. For example, it is known to provide material handling systems with vacuum cups that engage a substantially flat object or panel to lift and move the object to a desired location. The vacuum cup(s) are brought into engagement with the object, and a vacuum source communicating with the cup is actuated to create a vacuum between the object and the vacuum cup such that the object is retained by the cup. The object is then repositioned and either stripped from the vacuum cup while the vacuum source remains operational or the vacuum source is deactivated to release the object from the vacuum cup.
During lifting and transportation, it is important that the object is securely held by the material handling system and therefore important that the vacuum level is sufficient to ensure that the object remains secured to the pick and place material handling system. As the device is used, the cups, including the sealing lip located about the peripheral edge of the cup, wear and fail to tightly seal the vacuum cup against the object. Further the seal can easily become damaged due to the harshness of the environment resulting in the creation of a leak in the seal. Since the vacuum is generated by the supply of an air flow in a rubber tube line, any portion of the supply line is also subject to damage thereby creating potential leaks in the line that supplies the air resulting in an insufficient supply of air to create the necessary vacuum to pick up the workpiece with the material handling system. In addition, a material handling system may have multiple cups, for example four or more vacuum cups all connected to a single vacuum source. Accordingly, once the cups engage an object, such as an automotive panel, actuation of the vacuum source draws a vacuum equally on all four cups. However, if one of the cups is not properly sealed or damage to the supply line has created a leak, a disproportionate amount of the vacuum escapes through the unsealed cup and/or leaky supply line. Thus, even if the remaining cups are properly sealed against the automotive panel, the resultant vacuum may not have sufficient strength to lift and transfer the panel. The problem generally results in down time of the production line associated with the material handling system that leaks until such leaks can be corrected.